What are the causes of Lake Sevan eutrophication
Lake Sevan is garner of 35 billion cubic meters fresh water for the Republic of Armenia and the entire Caucasus. But today the water of Sevan wat is not clean, it is hampered by a number of factors.
Since 1930s as a result of the indiscriminate use of Sevan Lake water ecological balance of Sevan Lake was disturbed. From 1933 to 2000 the lake level has dropped 19.6 meters as a result of industrial exploitation and the volume was reduced from 58.5 billion cubic meters to 32.5 billion cubic meters.
The National Academy of Sciences Hydro-ecology and Ichthyology Institute scientific researches have shown that one of the main reasons for eutrophication is lake level dropping.
In lake aging process Lake slowing has a protective role in the water layer of constant temperature of 4C at the bottom of the lake. It does not allow the slime to be mixed the lake water. If the volume is reduced in the lake, the protective layer is being reduced too, and as a result lake starts to eutrophy. This layer can be restored by raising the water level.
The authorities envisage that Sevan will reach the mark of 1903.5 m in 2031. According to some sources, during the Soviet era of Lake Sevan level was lowered arguing that large amounts of water are being evaporated. Today, the water continues being released, because of lack of irrigation water. But the real reason is saving oligarchs' houses built on the lakeside.
Despite the efforts of the authorities, the water level rises and the illegally built houses remain under water.